问题描述
我很喜欢 C# 中的扩展方法,但在向静态类(例如 Console)添加扩展方法方面没有取得任何成功.
I'm a fan of extension methods in C#, but haven't had any success adding an extension method to a static class, such as Console.
例如,如果我想向控制台添加一个名为WriteBlueLine"的扩展,以便我可以:
For example, if I want to add an extension to Console, called 'WriteBlueLine', so that I can go:
Console.WriteBlueLine("This text is blue");
我尝试通过添加一个本地公共静态方法,将 Console 作为this"参数...但没有骰子!
I tried this by adding a local, public static method, with Console as a 'this' parameter... but no dice!
public static class Helpers {
public static void WriteBlueLine(this Console c, string text)
{
Console.ForegroundColor = ConsoleColor.Blue;
Console.WriteLine(text);
Console.ResetColor();
}
}
这并没有向控制台添加WriteBlueLine"方法……我做错了吗?还是要求不可能的?
This didn't add a 'WriteBlueLine' method to Console... am I doing it wrong? Or asking for the impossible?
推荐答案
没有.扩展方法需要对象的实例变量(值).但是,您可以围绕 ConfigurationManager
接口编写静态包装器.如果您实现包装器,则不需要扩展方法,因为您可以直接添加该方法.
No. Extension methods require an instance variable (value) for an object. You can however, write a static wrapper around the ConfigurationManager
interface. If you implement the wrapper, you don't need an extension method since you can just add the method directly.
public static class ConfigurationManagerWrapper
{
public static ConfigurationSection GetSection( string name )
{
return ConfigurationManager.GetSection( name );
}
.....
public static ConfigurationSection GetWidgetSection()
{
return GetSection( "widgets" );
}
}
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